Tape and reel packaging system for single-in-line electronic circuits

Abstract: An environmentally friendly packaging system is provided for packaging single-in-line type electronic circuits (1), which includes a perforated paper carrier tape (11) and an adhesive bonding tape (10). This tape and reel packaging system allows said circuits to be fixed horizontally in the reel, but ensures at the same time a smooth transfer of said circuits into a vertical position upon unreeling, thereby guaranteeing troublefree pick-up of these circuits either manually or by pick-up tools of automated pick and place machinery.

Description: Field of the invention: This invention relates in general to a tape and reel packaging system for single-in-line electronic circuits, having particular utilization in the field of automated pick and place unit. It relates more specifically to a packaging system that is environmentally friendly because it only uses basic materials that are biodegradable. It provides storage for said components in a horizontal position on the reel, thereby assuring the mechanical protection of the units and achieving the maximum packaging density. The invention further provides an easy method for assembling the circuits into the reel. The invention more specifically comprises a perforated paper carrier tape on which the circuits to be stored and transported are positioned in predeterminated locations and are maintained in these locations by means of an adhesive bonding tape, securing the fixation of the circuits during transportation. The invention also relates to apparatus designed for manipulation of the packaging system in such a way that the circuits are presented in an upright position at the pick and place unit of an automated component assembly equipment, thereby guaranteeing a smooth and easy release of the circuits from the packaging system. Background of the invention: Electronic circuits very frequently incorporate many differently shaped components which are assembled by means of highly automated machinery. These electronic circuits are then furtheron assembled into a finished product unit. From an economic standpoint here too it is highly desirable to automate as much as possible these assembly operations. To be able to do so, mechanisms and equipment must be available enabling the mechanized delivery of these components at the pick and place robotized head of an automated assembly equipment, allowing the assembly of such circuits into a finished product unit. A large number of such packaging systems and assembly machinery have thus been developed in the past with very large success for leadless components such as capacitors, resistors, diodes, integrated circuits and transistors in surface mount design. Much more limited success has been reached for packaging circuits with leads or terminals into a similar system ready for automated processing into finished product units. Because of the very fragile nature of these terminals, handling of such components may easily cause bending of one or more of these leads, thereby deteriorating lead coplanarity and originating problems at insertion of the component into a further subassembly that are difficult to overcome. Such problems can originate frequent machine stops of the automated equipment and result in defective subassemblies. Packaging systems have been developed that have eliminated the above problem and still allow presentation of the components at the pick and place workstations in their application to subassemblies. A previously patented example of such a packaging system has been disclosed in U.S. patent N° 4,583,641 granted April 22, 1986 to John R. Gelzer and was further developed in U.S. patent N° 5,312,015 granted May 17, 1994 to the same inventor. That prior art packaging system consisted of an elongated plastic carrier tape to which a secondary plastic packaging tape was removably secured and the two tapes cooperatively retained said articles in loop-form assemblies. The plastic packaging tape was mechanically interconnected to the plastic carrier tape by means which enabled the two tapes to be readily separated from each other at the assembly point, thereby releasing said article for pick and place operations. Obvious drawbacks of the above described system are the necessity for very specific equipment to make possible taping and reeling of said components and also for same specific equipment to allow releasing of said components at the pick & place workstations. Furthermore this complex packaging system requires state-of-the art handling equipment. Besides, at the point were the two tapes are mechanically separated, lots of plastic materials are accumulated that have proven to be difficultly reusable, but on the contrary are simply disposed off as waste. According to US-A-3 906 614 electrical components are positioned almost horizontally on a carrier tape, wherein lead terminals of the components protrude through through-holes of the carrier tape. Summary of the invention In accordance with this invention, a packaging system is provided that is capable of accepting electrical components with single in-line type electrodes and to provide protection for those components subsequent to their utilization in an automated assembly line. In contrast to the prior art according to US-A-4 583 641 and US-A-5 312 015 however, the latter system offers a much easier concept of packaging, utilising for example biodegradable paper materials, and not requiring very sophisticated and expensive handling apparatus. The packaging system of this invention as defined in claim 1 includes a carrier tape, which is perforated at repeatedly spaced distances allowing insertion of the components lead terminals by means of a simple insertion tool. Once inserted into the carrier tape, said electronic circuits are firmly secured in place by means of an adhesive tape allowing fixation of the lead terminals onto the back of the carrier tape. Upon advancing this packaging system during the 'reeling process,' said electronic circuits automatically switch from a vertical position at insertion into the carrier tape, to a horizontal position, at reeling, thereby ensuring an optimal packaging density of the assembled reel. At the same time the mechanical protection of the parts is guaranteed. The reels are typically made out of standard cardboard raw materials. An advantage of this packaging system is that is retains the electronic circuits in the desired orientation that is compatible with automated apparatus at the pick and place workstation of the automated assembly line. However, despite the fact that said electronic circuits lie in horizontal position on the packaged reel, they readily return into a precise vertical upright position at unreeling by means of a simple tooling typically designed for this purpose. Therefore, in accordance with this invention, specific apparatus is provided for effecting manipulation of the carrier tape in such a way to release the electronic circuits from the adhesive tape, thereby returning said components into an upright position, allowing easy pick-up either manually or at the robotized pick and place system of the automated assembly machine, without the need for specific tooling or equipment. In the illustrative embodiment of this apparatus, a simple feeder unit is described in order to allow said electronic components to return from their horizontal position on the reel into a vertical upright position typically needed at the pick & place workstation. Obviously the horizontal position of said electronic components on the reel offers superior protection against damage of the lead terminals or deterioration of the lead coplanarity compared to prior art systems whereby said components are transported in a vertical position. The article packaging system of this invention is of particular utility because it only uses biodegradable basic raw materials thereby ensuring a much lower environmental threat with respect to production of waste. These and other objects and advantages of the invention will be readily apparent from the following detailed description of illustrative embodiments of the invention and the accompanying drawings thereof. Description of the drawing figures Fig. 1 is a perspective view of a single-in-line (SIL) electronic circuit. Fig. 2 is a fragmentary sectional view of a SIL circuit with straight lead terminals. Fig. 3 is a fragmentary sectional view of a SIL circuit with snap-in lead terminals Fig. 4 is a fragmentary perspective view of a length of the packaging system embodying this invention and including a carrier tape and an adhesive tape partially assembled with SIL electronic circuits. Fig. 5 is a fragmentary enlarged view of a grid hole in Fig. 4. Fig. 6 is a diagrammatic illustration of the mechanical components for effecting automated reel taping of said SIL circuits using the packaging system of this invention. Fig. 7 is a fragmentary sectional view taken along a plane defined by line A-A in Fig. 4. Fig. 8 is a front and side view of an assembled reel using the packaging system of this invention. Fig. 9 is a diagrammatic illustration of the mechanical components for affecting automatic unreeling of said SIL circuits at the pick and place workstation of an automated assembly equipment. Description of the illustrative embodiment of the invention Referring to Fig. 1, a single-in-line electronic circuit 1 , hereafter called SIL circuit, is composed of a basic substrate 2 carrying the different electronic functions, carrying eventually add-on components 3 and a plurality of lead terminals 4. These lead terminals all are grouped on one lateral side of said substrate, therefore called single-in-line circuits. Lead spacings, often called grid, typically are 100 microns or 2.54 mm and the number of terminals can vary from 2 to n, n being a integer number higher than 2. Although lead spacings of 100 microns are described as being typical, it will be understood that other lead spacings may be utilised. In some specified applications the electronic functions of said SIL unit can be protected against humidity or mechanical damage by an appropriate coating such as an epoxy resin or a phenolic resin. Fig. 2 shows a configuration of a SIL circuit having straight lead terminals 5 . A variation often used in electronics is the so-called snap-in leadform of the terminals 6 , as shown in Fig. 3. Snap-in leads have the advantage over straight leads that they guarantee that the circuits are mechanically fixed in the positioning holes of the printed circuit board assembly at insertion and that a correct snap-off of the electronic circuit is always respected. Having reference to Fig. 4 a basic packaging system of this invention designated generally by the numeral 10 is shown in a horizontal planar orientation as would be appropriate for either the filling of the tape with the SIL circuits or for subsequent removal of said SIL circuits from the tape. The basic embodiment as shown in Fig. 4 comprises a carrier tape 11 and an adhesive tape 12. The carrier tape 11 is formed from a strip of a suitable paper material having appropriate characteristics of flexibility and structural strength. It is of a width that is sufficient to accommodate the length of the particular electronic SIL circuits that are to be packaged therein, and has a sufficient thickness in order to provide the necessary structural rigidity during transport movements, but still enables mechanical manipulation by the assembly equipment. The adhesive tape 12 is from a high grade, printable saturated paper backing coated with a specially formulated latex pressure sensitive adhesive system. It exhibits adequate structural strength and resilient flexibility to enable assembly with the carrier tape 11. In order to perform the function of positioning the SIL units on the carrier tape 11, the tape is formed with a plurality of holes 13 in a predetermined grid pattern that is perfectly matched to the number of lead terminals on said SIL electronic circuit. These holes 13 are dimensioned to receive these lead terminals with those leads thus projecting through the carrier tape. Obviously, forming of a grid pattern of the holes 13 enables any SIL unit physical outlook to be located at the desired relative position on the packaging system of this invention. It will also be understood that the grid holes 13 may be modified in accordance with the specifications for a particular SIL circuit destinated to be packaged in the packaging system of this invention. Having reference to Fig. 5 the grid holes 13 may incorporate an additional cut 15 in order to facilitate the unloading of SIL electronic circuits with snap-in lead forms. Both the carrier tape 11 and the adhesive tape 12 are manufactured from low cost basic materials that offer the exceptional advantage of being totally biodegradable. Compared to the prior art, the packaging system of this invention thus provides an environmentally safe and friendly operation. It will be understood that the width of the carrier tape 11 and the adhesive tape 12 are determined by the physical dimension of the SIL units to be packaged. However, it is desirable that the packaging system will be fabricated in several standardized width sizes that are matched to the various types of automated machinery with which the packaging system may be used. The pressure sensitive adhesive system employed in the adhesive tape 12 serves to locate the protruding lead terminals firmly to the adhesive tape 12 thereby ensuring retention of the SIL circuits in the packaging system of this invention. Assembly of the adhesive tape 12 with the carrier tape 11 can be accomplished by a relatively simple technique. The SIL circuits will first be placed on the carrier tape 11 with their respective lead terminals inserted in the holes 13 of said carrier tape 11 and thus fixed in position on the surface of the carrier tape. Once this has been accomplished the adhesive tape 12 may then be applied to the backside of said carrier tape using a specifically dedicated tool that exercises a transversal pressure to said adhesive tape. Disassembly of the adhesive tape from the carrier tape can be affected by a simple movement of pulling the adhesive tape in a reverse relationship to itself. Evidently these concepts can easily be integrated into the design of an automated tape and reel machine suited for the packaging system of this invention. To further enhance the usefulness and capabilities of this packaging system, the system of the invention is provided with indexing means through formation of a series of longitudinally spaced indexing holes 14 which, if desired, may be located at each marginal edge of the carrier tape 11. These indexing holes 14 are designed to interfit with the sprocket wheels of either the mechanisms for assembly of said packaging system with SIL circuits or the unloading of those circuits from the packaging system or any other mechanism operating with said packaging system. These indexing holes 14 are located in the carrier tape such that they will be oriented in specific dimensional relationship to the grid holes 13 so that it is possible by means of such indexing holes to either precisely locate the carrier tape 11 at a SIL loading station or precisely locate said carrier tape at a SIL unloading station. With the indexing holes 14 located in predetermined relationship with respect to the grid holes 13, it is assured that other mechanisms will be capable of positioning the SIL circuits in the locating means or to remove them from that position for subsequent use in automated systems. In using the tape indexing means in conjunction with the loading of the circuits, it will be noted that the carrier tape 11 may thus be positively fixed during those sequential operations wherein an equipment may mechanically load the circuits onto the carrier tape and a mechanical tool can automatically perform assembly of the bonding and carrier tapes. Although indexing holes 14 are illustrated, it will be understood that other indexing means may be utilized. Having thus described the packaging system of this invention, the functioning of same packaging system 10 to enable insertion of SIL electronic circuits and subsequent reel taping is diagrammatically illustrated in Fig. 6. On the one end of the insertion apparatus, the carrier tape 11 is mechanically advanced to the area where the SIL circuits are to be inserted by means of the sprocket wheel 20 . The sprocket pins on said sprocket wheel are of a configuration and size to cooperatively project through the respective sprocket holes 14 and to effect longitudinal displacement of the carrier tape. At the insertion station 31 the single-in-line electronic circuit is vertically plugged using its lead terminal pins into the grid holes 13 of the carrier tape 11 . Upon advancement of the carrier tape after insertion of the SIL unit, a specifically designed tool 23 of the insertion apparatus forces said SIL unit to be tilted to its side 32, with the lead terminals remaining however in the grid holes 13. Simultaneously with this operation, the adhesive tape 12 is presented between the underside of the carrier tape 11 and a mechanical tool 24. Said adhesive tape 12 is unrolled from a reel 21 of adhesive tape material and driven forward to the insertion area of the equipment by means of a driving wheel 22. Said adhesive tape is then further guided over the mechanical tool 24 of the insertion equipment. Simultaneously with the above described tilting operation of the SIL circuit the tool 24 exerts a pressure force on the bottom side of the adhesive, thereby securely fixing the lead terminals of the SIL circuit to the carrier tape. Upon further advancing the carrier tape to the right side of the insertion equipment, the assembled packaging system is further deviated to position 33 whereafter the SIL circuits are forced to lie almost in a horizontal position with respect to said carrier tape. At the end of the insertion operation said SIL electronic circuits are wound on a reel 25 using techniques and materials which are well known to those skilled in the art. A more detailed perspective view along plane A-A in Fig. 4 is presented in Fig. 7 and illustrates the different characteristics of the assembled packaging system of this invention. The SIL electronic circuit 1 has an inclined position with respect to the carrier tape 11 and the connecting pins or lead terminals of said circuit are securely fixed to said carrier tape by means of the adhesive tape 12, whereby it can be clearly seen that the interconnection between carrier tape and bonding tape takes place at the location between two ranges of grid holes 13 and on the underside of said carrier tape. A completely assembled reel 25 of the SIL circuits, using the packaging system of this invention, is illustrated in Fig. 8. Such reels are completely compatible with the mechanics of automated pick and place machinery and will not be described here further since these mechanical concepts are well known to those skilled in this particular art. Unloading of the assembled SIL circuits using the packaging system of this invention is schematically illustrated in Fig. 9. The reel 25 with said SIL circuits is unreeled using mechanical tools which are well known to those skilled in the art, and will not be described in this disclosure. The unreeled tape is then advanced over a guiding wheel 26 of an adequate feeder unit 40. A specifically designed square shaped mechanical tool 27 of said feeder unit 40 is employed to bring the SIL circuits again from their quasi horizontal position 41 on the reel tape to the vertical position 42 at the pick and place station 43 of the automated assembly machinery, said pick and place station being the workstation where the SIL circuits are unloaded from the tape and subsequently placed in the through-holes of the printed circuit board. Said feeder unit thus being specifically designed for enabling a vertical distribution of said SIL circuits at the pick and place station, it is obvious that the pick up of said SIL units may be achieved either by automatic or manual pick up. In the vertical position said circuits can be easily removed from the packaging system with very little force. The empty packaging system is then sorted out of the machine using a sprocket wheel mechanism 28. In describing the packaging system embodying this invention, the carrier and bonding tapes were generally described as being fabricated from paper type materials exhibiting the requisite structural strength and flexible characteristic. In this way an environmentally friendly packaging system is provided to the users. However, materials other than paper such as for example synthetic resins or plastics may be utilized in fabrication of either or both carrier tape and bonding tape. The several embodiments of the packaging system of this invention have been illustrated and described as having only one row of assembled circuits between any two adjacent points of interconnection between the carrier tape and the bonding tape. However, this basic configuration is not to be considered limitative as to the practice of this invention. It will be apparent from the above description of the different embodiments of this invention that a novel packaging system has been provided for fulfilling the requirements of fully automated component handling systems. The described packaging system performs a basic packaging function but more importantly, performs a packaging function in which each of the packaged circuits is precisely positioned in a predetermined orientation, so that they can be readily handled by automated machine mechanisms throughout a manufacturing process including ultimate utilization of the circuits, but also transportation and storage or other functions. The packaging system provided by this invention is also capable of modification to accommodate variously configured circuits while retaining the ability to implement the invention as defined in the claims.

Claims: A tape and reel packaging system for single-in-line (SIL) electronic circuits disposed seriatim in predetermined relationship, consisting of (a) a primary package and (b) a secondary package, whereby the primary package comprises a carrier tape 11 and an adhesive tape 12 combined in such a way that said SIL circuits 1 are positioned almost horizontally in the secondary package, thereby ensuring the maximum packaging density of the secondary package and an effective protection against lead damage or deterioration of lead coplanarity, (1) said carrier tape 11 , consisting of a strip of suitable paper material or for example synthetic resins or plastics material having appropriate characteristics of flexibility and structural strength, having a plurality of locating through-holes 13 in a predetermined grid pattern disposed seriatim along a longitudinal axis of said carrier tape 11 in spaced relationship, each of said locating through-holes 13 designed to cooperatively engage with at least one SIL circuit 1 by protrusion of its lead terminals 4 in order to releasable position that SIL circuit 1 in a predetermined location and orientation with respect of said carrier tape 11, said carrier tape 11 also being provided with a series of longitudinally spaced indexing holes 14 at each marginal edge and located in a predetermined relationship to said locating through-holes 13, thereby assuring precise positioning of said carrier tape 11 at a loading or unloading station for said SIL circuits 1, (2) said adhesive tape 12, consisting of a high grade paper backing or for example synthetic resins or plastics material coated with a specially formulated pressure sensitive adhesive system, disposed in longitudinally extending relationship to said carrier tape 11 and overlying the lead terminals 4 of said SIL circuits 1 protruding to said locating through-holes 13 of said carrier tape 11, and wherein the secondary package is a reel 25 carrying the primary package with the single-in-line circuits 1. A tape and reel packaging system according to claim 1 wherein said single-in-line electronic circuits 1 have either straight lead terminals 5 or snap-in formed lead terminal 6. A tape and reel packaging system according to claim 2 wherein for one SIL circuit 1 the number of said lead terminals can vary from 2 to n, n being an integer number higher than 2. A tape and reel packaging system according to claim 1 wherein each of said article locating through-holes 13 may incorporate an additional cut 15 thereby facilitating the unloading of said SIL circuits 1. A tape manipulating apparatus for producing the packaging system according to claim 1, comprising (1) a specifically designed mechanical tool 23 for tilting the vertically inserted SIL circuits 1 from an upright to an almost horizontal position in said carrier tape 11, with the lead terminals 4 remaining however in the locating through-holes 13, and also comprising thereafter (2) a specifically designed mechanical tool 24 exerting a pressure force on the bottom of said adhesive tape 12, thereby securely fixing the lead terminals of said SIL circuit 1 to said carrier tape 11 and assuring said SIL circuits 1 to remain firmly positioned horizontally with respect to the combination of carrier tape 11 and adhesive tape 12 in the assembled reel 25, thereby ensuring optimum packaging density and protection of the SIL circuits 1 against lead damage. A tape manipulating apparatus for unloading the packaging system according to claim 1, comprising a feeder unit 40 comprising a specifically designed square-shaped mechanical tool 27 around part of which the primary package is guided to force said horizontally packaged SIL circuits 1 back from their almost horizontal position to a perfectly vertical position at the unloading station for said SIL circuits 1 from said tape packaging system, thereby assuring perfect vertical placement of said SIL circuits 1 in the corresponding through-holes of the printed circuit boards. A tape and reel packaging system according to claim 1 having one or more rows of assembled single-in-line circuits 1 between any two adjacent points of interconnection between said carrier tape 11 and said adhesive tape 12.

Inventors: BAUWENS LUCIEN, DESCHAMPS JEAN MARIE, VINCENT EDDY, BAUWENS, LUCIEN, DESCHAMPS, JEAN MARIE, VINCENT, EDDY
Applicants: ELECTROMAG N V, ELECTROMAG N.V.
Application year: 1994
Main classification: B65D73
IPC codes: H05K13, B65D73